Revert of SkTime::GetNSecs() (patchset #10 id:180001 of https://codereview.chromium.org/1422513003/ )

Reason for revert:
https://codereview.chromium.org/1412453006

Original issue's description:
> SkTime::GetNSecs()
>
>    - Move high-precision wall timers from tools/timer to SkTime.
>    - Implement SkTime::GetMSecs() in terms of SkTime::GetNSecs().
>    - Delete unused tools/timer code.
>
> I have no idea what's going on there in src/animator.
> I don't intend to investigate.
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/70084cbc16ee8162649f2601377feb6e49de0217
>
> CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Debug-CrOS_Link-Trybot
>
> Committed: https://skia.googlesource.com/skia/+/a1840d50e29fd95e4df2d1168fe54c34c2a5c30c

TBR=caryclark@google.com,reed@google.com,mtklein@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1417753003

1 files changed, 51 insertions, 0 deletions

diff --git a/tools/timer/SysTimer_posix.cpp b/tools/timer/SysTimer_posix.cpp
new file mode 100644
index 0000000000..4b7d708aab
--- /dev/null
+++ b/tools/timer/SysTimer_posix.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "SysTimer_posix.h"
+
+static double interval_in_ms(timespec start_clock, timespec end_clock)
+{
+    double duration_clock;
+    if ((end_clock.tv_nsec - start_clock.tv_nsec) < 0) {
+        duration_clock = (end_clock.tv_sec - start_clock.tv_sec - 1) * 1000;
+        duration_clock += (1000000000 + end_clock.tv_nsec - start_clock.tv_nsec) / 1000000.0;
+    } else {
+        duration_clock = (end_clock.tv_sec - start_clock.tv_sec) * 1000;
+        duration_clock += (end_clock.tv_nsec - start_clock.tv_nsec) / 1000000.0;
+    }
+    return duration_clock;
+}
+
+void SysTimer::startWall() {
+    if (-1 == clock_gettime(CLOCK_MONOTONIC, &fWall)) {
+        timespec none = {0, 0};
+        fWall = none;
+    }
+}
+void SysTimer::startCpu() {
+    if (-1 == clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &fCpu)) {
+        timespec none = {0, 0};
+        fCpu = none;
+    }
+}
+
+double SysTimer::endCpu() {
+    timespec end_cpu;
+    if (-1 == clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &end_cpu)) {
+        timespec none = {0, 0};
+        end_cpu = none;
+    }
+    return interval_in_ms(fCpu, end_cpu);
+}
+
+double SysTimer::endWall() {
+    timespec end_wall;
+    if (-1 == clock_gettime(CLOCK_MONOTONIC, &end_wall)) {
+        timespec none = {0, 0};
+        end_wall = none;
+    }
+    return interval_in_ms(fWall, end_wall);
+}